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1/*
2 * linux/fs/9p/trans_fd.c
3 *
4 * Fd transport layer. Includes deprecated socket layer.
5 *
6 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
7 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
8 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
9 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2
13 * as published by the Free Software Foundation.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to:
22 * Free Software Foundation
23 * 51 Franklin Street, Fifth Floor
24 * Boston, MA 02111-1301 USA
25 *
26 */
27
28#include <linux/in.h>
29#include <linux/module.h>
30#include <linux/net.h>
31#include <linux/ipv6.h>
32#include <linux/kthread.h>
33#include <linux/errno.h>
34#include <linux/kernel.h>
35#include <linux/un.h>
36#include <linux/uaccess.h>
37#include <linux/inet.h>
38#include <linux/idr.h>
39#include <linux/file.h>
40#include <linux/parser.h>
41#include <linux/slab.h>
42#include <net/9p/9p.h>
43#include <net/9p/client.h>
44#include <net/9p/transport.h>
45
46#include <linux/syscalls.h> /* killme */
47
48#define P9_PORT 564
49#define MAX_SOCK_BUF (64*1024)
50#define MAXPOLLWADDR 2
51
52/**
53 * struct p9_fd_opts - per-transport options
54 * @rfd: file descriptor for reading (trans=fd)
55 * @wfd: file descriptor for writing (trans=fd)
56 * @port: port to connect to (trans=tcp)
57 *
58 */
59
60struct p9_fd_opts {
61 int rfd;
62 int wfd;
63 u16 port;
64};
65
66/**
67 * struct p9_trans_fd - transport state
68 * @rd: reference to file to read from
69 * @wr: reference of file to write to
70 * @conn: connection state reference
71 *
72 */
73
74struct p9_trans_fd {
75 struct file *rd;
76 struct file *wr;
77 struct p9_conn *conn;
78};
79
80/*
81 * Option Parsing (code inspired by NFS code)
82 * - a little lazy - parse all fd-transport options
83 */
84
85enum {
86 /* Options that take integer arguments */
87 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
88};
89
90static const match_table_t tokens = {
91 {Opt_port, "port=%u"},
92 {Opt_rfdno, "rfdno=%u"},
93 {Opt_wfdno, "wfdno=%u"},
94 {Opt_err, NULL},
95};
96
97enum {
98 Rworksched = 1, /* read work scheduled or running */
99 Rpending = 2, /* can read */
100 Wworksched = 4, /* write work scheduled or running */
101 Wpending = 8, /* can write */
102};
103
104struct p9_poll_wait {
105 struct p9_conn *conn;
106 wait_queue_t wait;
107 wait_queue_head_t *wait_addr;
108};
109
110/**
111 * struct p9_conn - fd mux connection state information
112 * @mux_list: list link for mux to manage multiple connections (?)
113 * @client: reference to client instance for this connection
114 * @err: error state
115 * @req_list: accounting for requests which have been sent
116 * @unsent_req_list: accounting for requests that haven't been sent
117 * @req: current request being processed (if any)
118 * @tmp_buf: temporary buffer to read in header
119 * @rsize: amount to read for current frame
120 * @rpos: read position in current frame
121 * @rbuf: current read buffer
122 * @wpos: write position for current frame
123 * @wsize: amount of data to write for current frame
124 * @wbuf: current write buffer
125 * @poll_pending_link: pending links to be polled per conn
126 * @poll_wait: array of wait_q's for various worker threads
127 * @pt: poll state
128 * @rq: current read work
129 * @wq: current write work
130 * @wsched: ????
131 *
132 */
133
134struct p9_conn {
135 struct list_head mux_list;
136 struct p9_client *client;
137 int err;
138 struct list_head req_list;
139 struct list_head unsent_req_list;
140 struct p9_req_t *req;
141 char tmp_buf[7];
142 int rsize;
143 int rpos;
144 char *rbuf;
145 int wpos;
146 int wsize;
147 char *wbuf;
148 struct list_head poll_pending_link;
149 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
150 poll_table pt;
151 struct work_struct rq;
152 struct work_struct wq;
153 unsigned long wsched;
154};
155
156static void p9_poll_workfn(struct work_struct *work);
157
158static DEFINE_SPINLOCK(p9_poll_lock);
159static LIST_HEAD(p9_poll_pending_list);
160static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
161
162static void p9_mux_poll_stop(struct p9_conn *m)
163{
164 unsigned long flags;
165 int i;
166
167 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
168 struct p9_poll_wait *pwait = &m->poll_wait[i];
169
170 if (pwait->wait_addr) {
171 remove_wait_queue(pwait->wait_addr, &pwait->wait);
172 pwait->wait_addr = NULL;
173 }
174 }
175
176 spin_lock_irqsave(&p9_poll_lock, flags);
177 list_del_init(&m->poll_pending_link);
178 spin_unlock_irqrestore(&p9_poll_lock, flags);
179}
180
181/**
182 * p9_conn_cancel - cancel all pending requests with error
183 * @m: mux data
184 * @err: error code
185 *
186 */
187
188static void p9_conn_cancel(struct p9_conn *m, int err)
189{
190 struct p9_req_t *req, *rtmp;
191 unsigned long flags;
192 LIST_HEAD(cancel_list);
193
194 P9_DPRINTK(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
195
196 spin_lock_irqsave(&m->client->lock, flags);
197
198 if (m->err) {
199 spin_unlock_irqrestore(&m->client->lock, flags);
200 return;
201 }
202
203 m->err = err;
204
205 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
206 req->status = REQ_STATUS_ERROR;
207 if (!req->t_err)
208 req->t_err = err;
209 list_move(&req->req_list, &cancel_list);
210 }
211 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
212 req->status = REQ_STATUS_ERROR;
213 if (!req->t_err)
214 req->t_err = err;
215 list_move(&req->req_list, &cancel_list);
216 }
217 spin_unlock_irqrestore(&m->client->lock, flags);
218
219 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
220 P9_DPRINTK(P9_DEBUG_ERROR, "call back req %p\n", req);
221 list_del(&req->req_list);
222 p9_client_cb(m->client, req);
223 }
224}
225
226static int
227p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt)
228{
229 int ret, n;
230 struct p9_trans_fd *ts = NULL;
231
232 if (client && client->status == Connected)
233 ts = client->trans;
234
235 if (!ts)
236 return -EREMOTEIO;
237
238 if (!ts->rd->f_op || !ts->rd->f_op->poll)
239 return -EIO;
240
241 if (!ts->wr->f_op || !ts->wr->f_op->poll)
242 return -EIO;
243
244 ret = ts->rd->f_op->poll(ts->rd, pt);
245 if (ret < 0)
246 return ret;
247
248 if (ts->rd != ts->wr) {
249 n = ts->wr->f_op->poll(ts->wr, pt);
250 if (n < 0)
251 return n;
252 ret = (ret & ~POLLOUT) | (n & ~POLLIN);
253 }
254
255 return ret;
256}
257
258/**
259 * p9_fd_read- read from a fd
260 * @client: client instance
261 * @v: buffer to receive data into
262 * @len: size of receive buffer
263 *
264 */
265
266static int p9_fd_read(struct p9_client *client, void *v, int len)
267{
268 int ret;
269 struct p9_trans_fd *ts = NULL;
270
271 if (client && client->status != Disconnected)
272 ts = client->trans;
273
274 if (!ts)
275 return -EREMOTEIO;
276
277 if (!(ts->rd->f_flags & O_NONBLOCK))
278 P9_DPRINTK(P9_DEBUG_ERROR, "blocking read ...\n");
279
280 ret = kernel_read(ts->rd, ts->rd->f_pos, v, len);
281 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
282 client->status = Disconnected;
283 return ret;
284}
285
286/**
287 * p9_read_work - called when there is some data to be read from a transport
288 * @work: container of work to be done
289 *
290 */
291
292static void p9_read_work(struct work_struct *work)
293{
294 int n, err;
295 struct p9_conn *m;
296
297 m = container_of(work, struct p9_conn, rq);
298
299 if (m->err < 0)
300 return;
301
302 P9_DPRINTK(P9_DEBUG_TRANS, "start mux %p pos %d\n", m, m->rpos);
303
304 if (!m->rbuf) {
305 m->rbuf = m->tmp_buf;
306 m->rpos = 0;
307 m->rsize = 7; /* start by reading header */
308 }
309
310 clear_bit(Rpending, &m->wsched);
311 P9_DPRINTK(P9_DEBUG_TRANS, "read mux %p pos %d size: %d = %d\n", m,
312 m->rpos, m->rsize, m->rsize-m->rpos);
313 err = p9_fd_read(m->client, m->rbuf + m->rpos,
314 m->rsize - m->rpos);
315 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
316 if (err == -EAGAIN) {
317 clear_bit(Rworksched, &m->wsched);
318 return;
319 }
320
321 if (err <= 0)
322 goto error;
323
324 m->rpos += err;
325
326 if ((!m->req) && (m->rpos == m->rsize)) { /* header read in */
327 u16 tag;
328 P9_DPRINTK(P9_DEBUG_TRANS, "got new header\n");
329
330 n = le32_to_cpu(*(__le32 *) m->rbuf); /* read packet size */
331 if (n >= m->client->msize) {
332 P9_DPRINTK(P9_DEBUG_ERROR,
333 "requested packet size too big: %d\n", n);
334 err = -EIO;
335 goto error;
336 }
337
338 tag = le16_to_cpu(*(__le16 *) (m->rbuf+5)); /* read tag */
339 P9_DPRINTK(P9_DEBUG_TRANS,
340 "mux %p pkt: size: %d bytes tag: %d\n", m, n, tag);
341
342 m->req = p9_tag_lookup(m->client, tag);
343 if (!m->req || (m->req->status != REQ_STATUS_SENT &&
344 m->req->status != REQ_STATUS_FLSH)) {
345 P9_DPRINTK(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
346 tag);
347 err = -EIO;
348 goto error;
349 }
350
351 if (m->req->rc == NULL) {
352 m->req->rc = kmalloc(sizeof(struct p9_fcall) +
353 m->client->msize, GFP_NOFS);
354 if (!m->req->rc) {
355 m->req = NULL;
356 err = -ENOMEM;
357 goto error;
358 }
359 }
360 m->rbuf = (char *)m->req->rc + sizeof(struct p9_fcall);
361 memcpy(m->rbuf, m->tmp_buf, m->rsize);
362 m->rsize = n;
363 }
364
365 /* not an else because some packets (like clunk) have no payload */
366 if ((m->req) && (m->rpos == m->rsize)) { /* packet is read in */
367 P9_DPRINTK(P9_DEBUG_TRANS, "got new packet\n");
368 spin_lock(&m->client->lock);
369 if (m->req->status != REQ_STATUS_ERROR)
370 m->req->status = REQ_STATUS_RCVD;
371 list_del(&m->req->req_list);
372 spin_unlock(&m->client->lock);
373 p9_client_cb(m->client, m->req);
374 m->rbuf = NULL;
375 m->rpos = 0;
376 m->rsize = 0;
377 m->req = NULL;
378 }
379
380 if (!list_empty(&m->req_list)) {
381 if (test_and_clear_bit(Rpending, &m->wsched))
382 n = POLLIN;
383 else
384 n = p9_fd_poll(m->client, NULL);
385
386 if (n & POLLIN) {
387 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
388 schedule_work(&m->rq);
389 } else
390 clear_bit(Rworksched, &m->wsched);
391 } else
392 clear_bit(Rworksched, &m->wsched);
393
394 return;
395error:
396 p9_conn_cancel(m, err);
397 clear_bit(Rworksched, &m->wsched);
398}
399
400/**
401 * p9_fd_write - write to a socket
402 * @client: client instance
403 * @v: buffer to send data from
404 * @len: size of send buffer
405 *
406 */
407
408static int p9_fd_write(struct p9_client *client, void *v, int len)
409{
410 int ret;
411 mm_segment_t oldfs;
412 struct p9_trans_fd *ts = NULL;
413
414 if (client && client->status != Disconnected)
415 ts = client->trans;
416
417 if (!ts)
418 return -EREMOTEIO;
419
420 if (!(ts->wr->f_flags & O_NONBLOCK))
421 P9_DPRINTK(P9_DEBUG_ERROR, "blocking write ...\n");
422
423 oldfs = get_fs();
424 set_fs(get_ds());
425 /* The cast to a user pointer is valid due to the set_fs() */
426 ret = vfs_write(ts->wr, (__force void __user *)v, len, &ts->wr->f_pos);
427 set_fs(oldfs);
428
429 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
430 client->status = Disconnected;
431 return ret;
432}
433
434/**
435 * p9_write_work - called when a transport can send some data
436 * @work: container for work to be done
437 *
438 */
439
440static void p9_write_work(struct work_struct *work)
441{
442 int n, err;
443 struct p9_conn *m;
444 struct p9_req_t *req;
445
446 m = container_of(work, struct p9_conn, wq);
447
448 if (m->err < 0) {
449 clear_bit(Wworksched, &m->wsched);
450 return;
451 }
452
453 if (!m->wsize) {
454 if (list_empty(&m->unsent_req_list)) {
455 clear_bit(Wworksched, &m->wsched);
456 return;
457 }
458
459 spin_lock(&m->client->lock);
460 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
461 req_list);
462 req->status = REQ_STATUS_SENT;
463 P9_DPRINTK(P9_DEBUG_TRANS, "move req %p\n", req);
464 list_move_tail(&req->req_list, &m->req_list);
465
466 m->wbuf = req->tc->sdata;
467 m->wsize = req->tc->size;
468 m->wpos = 0;
469 spin_unlock(&m->client->lock);
470 }
471
472 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p pos %d size %d\n", m, m->wpos,
473 m->wsize);
474 clear_bit(Wpending, &m->wsched);
475 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
476 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
477 if (err == -EAGAIN) {
478 clear_bit(Wworksched, &m->wsched);
479 return;
480 }
481
482 if (err < 0)
483 goto error;
484 else if (err == 0) {
485 err = -EREMOTEIO;
486 goto error;
487 }
488
489 m->wpos += err;
490 if (m->wpos == m->wsize)
491 m->wpos = m->wsize = 0;
492
493 if (m->wsize == 0 && !list_empty(&m->unsent_req_list)) {
494 if (test_and_clear_bit(Wpending, &m->wsched))
495 n = POLLOUT;
496 else
497 n = p9_fd_poll(m->client, NULL);
498
499 if (n & POLLOUT) {
500 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
501 schedule_work(&m->wq);
502 } else
503 clear_bit(Wworksched, &m->wsched);
504 } else
505 clear_bit(Wworksched, &m->wsched);
506
507 return;
508
509error:
510 p9_conn_cancel(m, err);
511 clear_bit(Wworksched, &m->wsched);
512}
513
514static int p9_pollwake(wait_queue_t *wait, unsigned mode, int sync, void *key)
515{
516 struct p9_poll_wait *pwait =
517 container_of(wait, struct p9_poll_wait, wait);
518 struct p9_conn *m = pwait->conn;
519 unsigned long flags;
520
521 spin_lock_irqsave(&p9_poll_lock, flags);
522 if (list_empty(&m->poll_pending_link))
523 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
524 spin_unlock_irqrestore(&p9_poll_lock, flags);
525
526 schedule_work(&p9_poll_work);
527 return 1;
528}
529
530/**
531 * p9_pollwait - add poll task to the wait queue
532 * @filp: file pointer being polled
533 * @wait_address: wait_q to block on
534 * @p: poll state
535 *
536 * called by files poll operation to add v9fs-poll task to files wait queue
537 */
538
539static void
540p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
541{
542 struct p9_conn *m = container_of(p, struct p9_conn, pt);
543 struct p9_poll_wait *pwait = NULL;
544 int i;
545
546 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
547 if (m->poll_wait[i].wait_addr == NULL) {
548 pwait = &m->poll_wait[i];
549 break;
550 }
551 }
552
553 if (!pwait) {
554 P9_DPRINTK(P9_DEBUG_ERROR, "not enough wait_address slots\n");
555 return;
556 }
557
558 pwait->conn = m;
559 pwait->wait_addr = wait_address;
560 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
561 add_wait_queue(wait_address, &pwait->wait);
562}
563
564/**
565 * p9_conn_create - allocate and initialize the per-session mux data
566 * @client: client instance
567 *
568 * Note: Creates the polling task if this is the first session.
569 */
570
571static struct p9_conn *p9_conn_create(struct p9_client *client)
572{
573 int n;
574 struct p9_conn *m;
575
576 P9_DPRINTK(P9_DEBUG_TRANS, "client %p msize %d\n", client,
577 client->msize);
578 m = kzalloc(sizeof(struct p9_conn), GFP_KERNEL);
579 if (!m)
580 return ERR_PTR(-ENOMEM);
581
582 INIT_LIST_HEAD(&m->mux_list);
583 m->client = client;
584
585 INIT_LIST_HEAD(&m->req_list);
586 INIT_LIST_HEAD(&m->unsent_req_list);
587 INIT_WORK(&m->rq, p9_read_work);
588 INIT_WORK(&m->wq, p9_write_work);
589 INIT_LIST_HEAD(&m->poll_pending_link);
590 init_poll_funcptr(&m->pt, p9_pollwait);
591
592 n = p9_fd_poll(client, &m->pt);
593 if (n & POLLIN) {
594 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
595 set_bit(Rpending, &m->wsched);
596 }
597
598 if (n & POLLOUT) {
599 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
600 set_bit(Wpending, &m->wsched);
601 }
602
603 return m;
604}
605
606/**
607 * p9_poll_mux - polls a mux and schedules read or write works if necessary
608 * @m: connection to poll
609 *
610 */
611
612static void p9_poll_mux(struct p9_conn *m)
613{
614 int n;
615
616 if (m->err < 0)
617 return;
618
619 n = p9_fd_poll(m->client, NULL);
620 if (n < 0 || n & (POLLERR | POLLHUP | POLLNVAL)) {
621 P9_DPRINTK(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
622 if (n >= 0)
623 n = -ECONNRESET;
624 p9_conn_cancel(m, n);
625 }
626
627 if (n & POLLIN) {
628 set_bit(Rpending, &m->wsched);
629 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can read\n", m);
630 if (!test_and_set_bit(Rworksched, &m->wsched)) {
631 P9_DPRINTK(P9_DEBUG_TRANS, "sched read work %p\n", m);
632 schedule_work(&m->rq);
633 }
634 }
635
636 if (n & POLLOUT) {
637 set_bit(Wpending, &m->wsched);
638 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p can write\n", m);
639 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
640 !test_and_set_bit(Wworksched, &m->wsched)) {
641 P9_DPRINTK(P9_DEBUG_TRANS, "sched write work %p\n", m);
642 schedule_work(&m->wq);
643 }
644 }
645}
646
647/**
648 * p9_fd_request - send 9P request
649 * The function can sleep until the request is scheduled for sending.
650 * The function can be interrupted. Return from the function is not
651 * a guarantee that the request is sent successfully.
652 *
653 * @client: client instance
654 * @req: request to be sent
655 *
656 */
657
658static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
659{
660 int n;
661 struct p9_trans_fd *ts = client->trans;
662 struct p9_conn *m = ts->conn;
663
664 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n", m,
665 current, req->tc, req->tc->id);
666 if (m->err < 0)
667 return m->err;
668
669 spin_lock(&client->lock);
670 req->status = REQ_STATUS_UNSENT;
671 list_add_tail(&req->req_list, &m->unsent_req_list);
672 spin_unlock(&client->lock);
673
674 if (test_and_clear_bit(Wpending, &m->wsched))
675 n = POLLOUT;
676 else
677 n = p9_fd_poll(m->client, NULL);
678
679 if (n & POLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
680 schedule_work(&m->wq);
681
682 return 0;
683}
684
685static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
686{
687 int ret = 1;
688
689 P9_DPRINTK(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
690
691 spin_lock(&client->lock);
692
693 if (req->status == REQ_STATUS_UNSENT) {
694 list_del(&req->req_list);
695 req->status = REQ_STATUS_FLSHD;
696 ret = 0;
697 } else if (req->status == REQ_STATUS_SENT)
698 req->status = REQ_STATUS_FLSH;
699
700 spin_unlock(&client->lock);
701
702 return ret;
703}
704
705/**
706 * parse_opts - parse mount options into p9_fd_opts structure
707 * @params: options string passed from mount
708 * @opts: fd transport-specific structure to parse options into
709 *
710 * Returns 0 upon success, -ERRNO upon failure
711 */
712
713static int parse_opts(char *params, struct p9_fd_opts *opts)
714{
715 char *p;
716 substring_t args[MAX_OPT_ARGS];
717 int option;
718 char *options, *tmp_options;
719
720 opts->port = P9_PORT;
721 opts->rfd = ~0;
722 opts->wfd = ~0;
723
724 if (!params)
725 return 0;
726
727 tmp_options = kstrdup(params, GFP_KERNEL);
728 if (!tmp_options) {
729 P9_DPRINTK(P9_DEBUG_ERROR,
730 "failed to allocate copy of option string\n");
731 return -ENOMEM;
732 }
733 options = tmp_options;
734
735 while ((p = strsep(&options, ",")) != NULL) {
736 int token;
737 int r;
738 if (!*p)
739 continue;
740 token = match_token(p, tokens, args);
741 if (token != Opt_err) {
742 r = match_int(&args[0], &option);
743 if (r < 0) {
744 P9_DPRINTK(P9_DEBUG_ERROR,
745 "integer field, but no integer?\n");
746 continue;
747 }
748 }
749 switch (token) {
750 case Opt_port:
751 opts->port = option;
752 break;
753 case Opt_rfdno:
754 opts->rfd = option;
755 break;
756 case Opt_wfdno:
757 opts->wfd = option;
758 break;
759 default:
760 continue;
761 }
762 }
763
764 kfree(tmp_options);
765 return 0;
766}
767
768static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
769{
770 struct p9_trans_fd *ts = kmalloc(sizeof(struct p9_trans_fd),
771 GFP_KERNEL);
772 if (!ts)
773 return -ENOMEM;
774
775 ts->rd = fget(rfd);
776 ts->wr = fget(wfd);
777 if (!ts->rd || !ts->wr) {
778 if (ts->rd)
779 fput(ts->rd);
780 if (ts->wr)
781 fput(ts->wr);
782 kfree(ts);
783 return -EIO;
784 }
785
786 client->trans = ts;
787 client->status = Connected;
788
789 return 0;
790}
791
792static int p9_socket_open(struct p9_client *client, struct socket *csocket)
793{
794 struct p9_trans_fd *p;
795 int ret, fd;
796
797 p = kmalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
798 if (!p)
799 return -ENOMEM;
800
801 csocket->sk->sk_allocation = GFP_NOIO;
802 fd = sock_map_fd(csocket, 0);
803 if (fd < 0) {
804 P9_EPRINTK(KERN_ERR, "p9_socket_open: failed to map fd\n");
805 sock_release(csocket);
806 kfree(p);
807 return fd;
808 }
809
810 get_file(csocket->file);
811 get_file(csocket->file);
812 p->wr = p->rd = csocket->file;
813 client->trans = p;
814 client->status = Connected;
815
816 sys_close(fd); /* still racy */
817
818 p->rd->f_flags |= O_NONBLOCK;
819
820 p->conn = p9_conn_create(client);
821 if (IS_ERR(p->conn)) {
822 ret = PTR_ERR(p->conn);
823 p->conn = NULL;
824 kfree(p);
825 sockfd_put(csocket);
826 sockfd_put(csocket);
827 return ret;
828 }
829 return 0;
830}
831
832/**
833 * p9_mux_destroy - cancels all pending requests and frees mux resources
834 * @m: mux to destroy
835 *
836 */
837
838static void p9_conn_destroy(struct p9_conn *m)
839{
840 P9_DPRINTK(P9_DEBUG_TRANS, "mux %p prev %p next %p\n", m,
841 m->mux_list.prev, m->mux_list.next);
842
843 p9_mux_poll_stop(m);
844 cancel_work_sync(&m->rq);
845 cancel_work_sync(&m->wq);
846
847 p9_conn_cancel(m, -ECONNRESET);
848
849 m->client = NULL;
850 kfree(m);
851}
852
853/**
854 * p9_fd_close - shutdown file descriptor transport
855 * @client: client instance
856 *
857 */
858
859static void p9_fd_close(struct p9_client *client)
860{
861 struct p9_trans_fd *ts;
862
863 if (!client)
864 return;
865
866 ts = client->trans;
867 if (!ts)
868 return;
869
870 client->status = Disconnected;
871
872 p9_conn_destroy(ts->conn);
873
874 if (ts->rd)
875 fput(ts->rd);
876 if (ts->wr)
877 fput(ts->wr);
878
879 kfree(ts);
880}
881
882/*
883 * stolen from NFS - maybe should be made a generic function?
884 */
885static inline int valid_ipaddr4(const char *buf)
886{
887 int rc, count, in[4];
888
889 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
890 if (rc != 4)
891 return -EINVAL;
892 for (count = 0; count < 4; count++) {
893 if (in[count] > 255)
894 return -EINVAL;
895 }
896 return 0;
897}
898
899static int
900p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
901{
902 int err;
903 struct socket *csocket;
904 struct sockaddr_in sin_server;
905 struct p9_fd_opts opts;
906
907 err = parse_opts(args, &opts);
908 if (err < 0)
909 return err;
910
911 if (valid_ipaddr4(addr) < 0)
912 return -EINVAL;
913
914 csocket = NULL;
915
916 sin_server.sin_family = AF_INET;
917 sin_server.sin_addr.s_addr = in_aton(addr);
918 sin_server.sin_port = htons(opts.port);
919 err = __sock_create(read_pnet(¤t->nsproxy->net_ns), PF_INET,
920 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
921 if (err) {
922 P9_EPRINTK(KERN_ERR, "p9_trans_tcp: problem creating socket\n");
923 return err;
924 }
925
926 err = csocket->ops->connect(csocket,
927 (struct sockaddr *)&sin_server,
928 sizeof(struct sockaddr_in), 0);
929 if (err < 0) {
930 P9_EPRINTK(KERN_ERR,
931 "p9_trans_tcp: problem connecting socket to %s\n",
932 addr);
933 sock_release(csocket);
934 return err;
935 }
936
937 return p9_socket_open(client, csocket);
938}
939
940static int
941p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
942{
943 int err;
944 struct socket *csocket;
945 struct sockaddr_un sun_server;
946
947 csocket = NULL;
948
949 if (strlen(addr) >= UNIX_PATH_MAX) {
950 P9_EPRINTK(KERN_ERR, "p9_trans_unix: address too long: %s\n",
951 addr);
952 return -ENAMETOOLONG;
953 }
954
955 sun_server.sun_family = PF_UNIX;
956 strcpy(sun_server.sun_path, addr);
957 err = __sock_create(read_pnet(¤t->nsproxy->net_ns), PF_UNIX,
958 SOCK_STREAM, 0, &csocket, 1);
959 if (err < 0) {
960 P9_EPRINTK(KERN_ERR, "p9_trans_unix: problem creating socket\n");
961 return err;
962 }
963 err = csocket->ops->connect(csocket, (struct sockaddr *)&sun_server,
964 sizeof(struct sockaddr_un) - 1, 0);
965 if (err < 0) {
966 P9_EPRINTK(KERN_ERR,
967 "p9_trans_unix: problem connecting socket: %s: %d\n",
968 addr, err);
969 sock_release(csocket);
970 return err;
971 }
972
973 return p9_socket_open(client, csocket);
974}
975
976static int
977p9_fd_create(struct p9_client *client, const char *addr, char *args)
978{
979 int err;
980 struct p9_fd_opts opts;
981 struct p9_trans_fd *p;
982
983 parse_opts(args, &opts);
984
985 if (opts.rfd == ~0 || opts.wfd == ~0) {
986 printk(KERN_ERR "v9fs: Insufficient options for proto=fd\n");
987 return -ENOPROTOOPT;
988 }
989
990 err = p9_fd_open(client, opts.rfd, opts.wfd);
991 if (err < 0)
992 return err;
993
994 p = (struct p9_trans_fd *) client->trans;
995 p->conn = p9_conn_create(client);
996 if (IS_ERR(p->conn)) {
997 err = PTR_ERR(p->conn);
998 p->conn = NULL;
999 fput(p->rd);
1000 fput(p->wr);
1001 return err;
1002 }
1003
1004 return 0;
1005}
1006
1007static struct p9_trans_module p9_tcp_trans = {
1008 .name = "tcp",
1009 .maxsize = MAX_SOCK_BUF,
1010 .def = 1,
1011 .create = p9_fd_create_tcp,
1012 .close = p9_fd_close,
1013 .request = p9_fd_request,
1014 .cancel = p9_fd_cancel,
1015 .owner = THIS_MODULE,
1016};
1017
1018static struct p9_trans_module p9_unix_trans = {
1019 .name = "unix",
1020 .maxsize = MAX_SOCK_BUF,
1021 .def = 0,
1022 .create = p9_fd_create_unix,
1023 .close = p9_fd_close,
1024 .request = p9_fd_request,
1025 .cancel = p9_fd_cancel,
1026 .owner = THIS_MODULE,
1027};
1028
1029static struct p9_trans_module p9_fd_trans = {
1030 .name = "fd",
1031 .maxsize = MAX_SOCK_BUF,
1032 .def = 0,
1033 .create = p9_fd_create,
1034 .close = p9_fd_close,
1035 .request = p9_fd_request,
1036 .cancel = p9_fd_cancel,
1037 .owner = THIS_MODULE,
1038};
1039
1040/**
1041 * p9_poll_proc - poll worker thread
1042 * @a: thread state and arguments
1043 *
1044 * polls all v9fs transports for new events and queues the appropriate
1045 * work to the work queue
1046 *
1047 */
1048
1049static void p9_poll_workfn(struct work_struct *work)
1050{
1051 unsigned long flags;
1052
1053 P9_DPRINTK(P9_DEBUG_TRANS, "start %p\n", current);
1054
1055 spin_lock_irqsave(&p9_poll_lock, flags);
1056 while (!list_empty(&p9_poll_pending_list)) {
1057 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1058 struct p9_conn,
1059 poll_pending_link);
1060 list_del_init(&conn->poll_pending_link);
1061 spin_unlock_irqrestore(&p9_poll_lock, flags);
1062
1063 p9_poll_mux(conn);
1064
1065 spin_lock_irqsave(&p9_poll_lock, flags);
1066 }
1067 spin_unlock_irqrestore(&p9_poll_lock, flags);
1068
1069 P9_DPRINTK(P9_DEBUG_TRANS, "finish\n");
1070}
1071
1072int p9_trans_fd_init(void)
1073{
1074 v9fs_register_trans(&p9_tcp_trans);
1075 v9fs_register_trans(&p9_unix_trans);
1076 v9fs_register_trans(&p9_fd_trans);
1077
1078 return 0;
1079}
1080
1081void p9_trans_fd_exit(void)
1082{
1083 flush_work_sync(&p9_poll_work);
1084 v9fs_unregister_trans(&p9_tcp_trans);
1085 v9fs_unregister_trans(&p9_unix_trans);
1086 v9fs_unregister_trans(&p9_fd_trans);
1087}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Fd transport layer. Includes deprecated socket layer.
4 *
5 * Copyright (C) 2006 by Russ Cox <rsc@swtch.com>
6 * Copyright (C) 2004-2005 by Latchesar Ionkov <lucho@ionkov.net>
7 * Copyright (C) 2004-2008 by Eric Van Hensbergen <ericvh@gmail.com>
8 * Copyright (C) 1997-2002 by Ron Minnich <rminnich@sarnoff.com>
9 */
10
11#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
12
13#include <linux/in.h>
14#include <linux/module.h>
15#include <linux/net.h>
16#include <linux/ipv6.h>
17#include <linux/kthread.h>
18#include <linux/errno.h>
19#include <linux/kernel.h>
20#include <linux/un.h>
21#include <linux/uaccess.h>
22#include <linux/inet.h>
23#include <linux/file.h>
24#include <linux/parser.h>
25#include <linux/slab.h>
26#include <linux/seq_file.h>
27#include <net/9p/9p.h>
28#include <net/9p/client.h>
29#include <net/9p/transport.h>
30
31#include <linux/syscalls.h> /* killme */
32
33#define P9_PORT 564
34#define MAX_SOCK_BUF (1024*1024)
35#define MAXPOLLWADDR 2
36
37static struct p9_trans_module p9_tcp_trans;
38static struct p9_trans_module p9_fd_trans;
39
40/**
41 * struct p9_fd_opts - per-transport options
42 * @rfd: file descriptor for reading (trans=fd)
43 * @wfd: file descriptor for writing (trans=fd)
44 * @port: port to connect to (trans=tcp)
45 * @privport: port is privileged
46 */
47
48struct p9_fd_opts {
49 int rfd;
50 int wfd;
51 u16 port;
52 bool privport;
53};
54
55/*
56 * Option Parsing (code inspired by NFS code)
57 * - a little lazy - parse all fd-transport options
58 */
59
60enum {
61 /* Options that take integer arguments */
62 Opt_port, Opt_rfdno, Opt_wfdno, Opt_err,
63 /* Options that take no arguments */
64 Opt_privport,
65};
66
67static const match_table_t tokens = {
68 {Opt_port, "port=%u"},
69 {Opt_rfdno, "rfdno=%u"},
70 {Opt_wfdno, "wfdno=%u"},
71 {Opt_privport, "privport"},
72 {Opt_err, NULL},
73};
74
75enum {
76 Rworksched = 1, /* read work scheduled or running */
77 Rpending = 2, /* can read */
78 Wworksched = 4, /* write work scheduled or running */
79 Wpending = 8, /* can write */
80};
81
82struct p9_poll_wait {
83 struct p9_conn *conn;
84 wait_queue_entry_t wait;
85 wait_queue_head_t *wait_addr;
86};
87
88/**
89 * struct p9_conn - fd mux connection state information
90 * @mux_list: list link for mux to manage multiple connections (?)
91 * @client: reference to client instance for this connection
92 * @err: error state
93 * @req_lock: lock protecting req_list and requests statuses
94 * @req_list: accounting for requests which have been sent
95 * @unsent_req_list: accounting for requests that haven't been sent
96 * @rreq: read request
97 * @wreq: write request
98 * @tmp_buf: temporary buffer to read in header
99 * @rc: temporary fcall for reading current frame
100 * @wpos: write position for current frame
101 * @wsize: amount of data to write for current frame
102 * @wbuf: current write buffer
103 * @poll_pending_link: pending links to be polled per conn
104 * @poll_wait: array of wait_q's for various worker threads
105 * @pt: poll state
106 * @rq: current read work
107 * @wq: current write work
108 * @wsched: ????
109 *
110 */
111
112struct p9_conn {
113 struct list_head mux_list;
114 struct p9_client *client;
115 int err;
116 spinlock_t req_lock;
117 struct list_head req_list;
118 struct list_head unsent_req_list;
119 struct p9_req_t *rreq;
120 struct p9_req_t *wreq;
121 char tmp_buf[P9_HDRSZ];
122 struct p9_fcall rc;
123 int wpos;
124 int wsize;
125 char *wbuf;
126 struct list_head poll_pending_link;
127 struct p9_poll_wait poll_wait[MAXPOLLWADDR];
128 poll_table pt;
129 struct work_struct rq;
130 struct work_struct wq;
131 unsigned long wsched;
132};
133
134/**
135 * struct p9_trans_fd - transport state
136 * @rd: reference to file to read from
137 * @wr: reference of file to write to
138 * @conn: connection state reference
139 *
140 */
141
142struct p9_trans_fd {
143 struct file *rd;
144 struct file *wr;
145 struct p9_conn conn;
146};
147
148static void p9_poll_workfn(struct work_struct *work);
149
150static DEFINE_SPINLOCK(p9_poll_lock);
151static LIST_HEAD(p9_poll_pending_list);
152static DECLARE_WORK(p9_poll_work, p9_poll_workfn);
153
154static unsigned int p9_ipport_resv_min = P9_DEF_MIN_RESVPORT;
155static unsigned int p9_ipport_resv_max = P9_DEF_MAX_RESVPORT;
156
157static void p9_mux_poll_stop(struct p9_conn *m)
158{
159 unsigned long flags;
160 int i;
161
162 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
163 struct p9_poll_wait *pwait = &m->poll_wait[i];
164
165 if (pwait->wait_addr) {
166 remove_wait_queue(pwait->wait_addr, &pwait->wait);
167 pwait->wait_addr = NULL;
168 }
169 }
170
171 spin_lock_irqsave(&p9_poll_lock, flags);
172 list_del_init(&m->poll_pending_link);
173 spin_unlock_irqrestore(&p9_poll_lock, flags);
174
175 flush_work(&p9_poll_work);
176}
177
178/**
179 * p9_conn_cancel - cancel all pending requests with error
180 * @m: mux data
181 * @err: error code
182 *
183 */
184
185static void p9_conn_cancel(struct p9_conn *m, int err)
186{
187 struct p9_req_t *req, *rtmp;
188 LIST_HEAD(cancel_list);
189
190 p9_debug(P9_DEBUG_ERROR, "mux %p err %d\n", m, err);
191
192 spin_lock(&m->req_lock);
193
194 if (m->err) {
195 spin_unlock(&m->req_lock);
196 return;
197 }
198
199 m->err = err;
200
201 list_for_each_entry_safe(req, rtmp, &m->req_list, req_list) {
202 list_move(&req->req_list, &cancel_list);
203 WRITE_ONCE(req->status, REQ_STATUS_ERROR);
204 }
205 list_for_each_entry_safe(req, rtmp, &m->unsent_req_list, req_list) {
206 list_move(&req->req_list, &cancel_list);
207 WRITE_ONCE(req->status, REQ_STATUS_ERROR);
208 }
209
210 spin_unlock(&m->req_lock);
211
212 list_for_each_entry_safe(req, rtmp, &cancel_list, req_list) {
213 p9_debug(P9_DEBUG_ERROR, "call back req %p\n", req);
214 list_del(&req->req_list);
215 if (!req->t_err)
216 req->t_err = err;
217 p9_client_cb(m->client, req, REQ_STATUS_ERROR);
218 }
219}
220
221static __poll_t
222p9_fd_poll(struct p9_client *client, struct poll_table_struct *pt, int *err)
223{
224 __poll_t ret;
225 struct p9_trans_fd *ts = NULL;
226
227 if (client && client->status == Connected)
228 ts = client->trans;
229
230 if (!ts) {
231 if (err)
232 *err = -EREMOTEIO;
233 return EPOLLERR;
234 }
235
236 ret = vfs_poll(ts->rd, pt);
237 if (ts->rd != ts->wr)
238 ret = (ret & ~EPOLLOUT) | (vfs_poll(ts->wr, pt) & ~EPOLLIN);
239 return ret;
240}
241
242/**
243 * p9_fd_read- read from a fd
244 * @client: client instance
245 * @v: buffer to receive data into
246 * @len: size of receive buffer
247 *
248 */
249
250static int p9_fd_read(struct p9_client *client, void *v, int len)
251{
252 int ret;
253 struct p9_trans_fd *ts = NULL;
254 loff_t pos;
255
256 if (client && client->status != Disconnected)
257 ts = client->trans;
258
259 if (!ts)
260 return -EREMOTEIO;
261
262 if (!(ts->rd->f_flags & O_NONBLOCK))
263 p9_debug(P9_DEBUG_ERROR, "blocking read ...\n");
264
265 pos = ts->rd->f_pos;
266 ret = kernel_read(ts->rd, v, len, &pos);
267 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
268 client->status = Disconnected;
269 return ret;
270}
271
272/**
273 * p9_read_work - called when there is some data to be read from a transport
274 * @work: container of work to be done
275 *
276 */
277
278static void p9_read_work(struct work_struct *work)
279{
280 __poll_t n;
281 int err;
282 struct p9_conn *m;
283
284 m = container_of(work, struct p9_conn, rq);
285
286 if (m->err < 0)
287 return;
288
289 p9_debug(P9_DEBUG_TRANS, "start mux %p pos %zd\n", m, m->rc.offset);
290
291 if (!m->rc.sdata) {
292 m->rc.sdata = m->tmp_buf;
293 m->rc.offset = 0;
294 m->rc.capacity = P9_HDRSZ; /* start by reading header */
295 }
296
297 clear_bit(Rpending, &m->wsched);
298 p9_debug(P9_DEBUG_TRANS, "read mux %p pos %zd size: %zd = %zd\n",
299 m, m->rc.offset, m->rc.capacity,
300 m->rc.capacity - m->rc.offset);
301 err = p9_fd_read(m->client, m->rc.sdata + m->rc.offset,
302 m->rc.capacity - m->rc.offset);
303 p9_debug(P9_DEBUG_TRANS, "mux %p got %d bytes\n", m, err);
304 if (err == -EAGAIN)
305 goto end_clear;
306
307 if (err <= 0)
308 goto error;
309
310 m->rc.offset += err;
311
312 /* header read in */
313 if ((!m->rreq) && (m->rc.offset == m->rc.capacity)) {
314 p9_debug(P9_DEBUG_TRANS, "got new header\n");
315
316 /* Header size */
317 m->rc.size = P9_HDRSZ;
318 err = p9_parse_header(&m->rc, &m->rc.size, NULL, NULL, 0);
319 if (err) {
320 p9_debug(P9_DEBUG_ERROR,
321 "error parsing header: %d\n", err);
322 goto error;
323 }
324
325 p9_debug(P9_DEBUG_TRANS,
326 "mux %p pkt: size: %d bytes tag: %d\n",
327 m, m->rc.size, m->rc.tag);
328
329 m->rreq = p9_tag_lookup(m->client, m->rc.tag);
330 if (!m->rreq || (m->rreq->status != REQ_STATUS_SENT)) {
331 p9_debug(P9_DEBUG_ERROR, "Unexpected packet tag %d\n",
332 m->rc.tag);
333 err = -EIO;
334 goto error;
335 }
336
337 if (m->rc.size > m->rreq->rc.capacity) {
338 p9_debug(P9_DEBUG_ERROR,
339 "requested packet size too big: %d for tag %d with capacity %zd\n",
340 m->rc.size, m->rc.tag, m->rreq->rc.capacity);
341 err = -EIO;
342 goto error;
343 }
344
345 if (!m->rreq->rc.sdata) {
346 p9_debug(P9_DEBUG_ERROR,
347 "No recv fcall for tag %d (req %p), disconnecting!\n",
348 m->rc.tag, m->rreq);
349 p9_req_put(m->client, m->rreq);
350 m->rreq = NULL;
351 err = -EIO;
352 goto error;
353 }
354 m->rc.sdata = m->rreq->rc.sdata;
355 memcpy(m->rc.sdata, m->tmp_buf, m->rc.capacity);
356 m->rc.capacity = m->rc.size;
357 }
358
359 /* packet is read in
360 * not an else because some packets (like clunk) have no payload
361 */
362 if ((m->rreq) && (m->rc.offset == m->rc.capacity)) {
363 p9_debug(P9_DEBUG_TRANS, "got new packet\n");
364 m->rreq->rc.size = m->rc.offset;
365 spin_lock(&m->req_lock);
366 if (m->rreq->status == REQ_STATUS_SENT) {
367 list_del(&m->rreq->req_list);
368 p9_client_cb(m->client, m->rreq, REQ_STATUS_RCVD);
369 } else if (m->rreq->status == REQ_STATUS_FLSHD) {
370 /* Ignore replies associated with a cancelled request. */
371 p9_debug(P9_DEBUG_TRANS,
372 "Ignore replies associated with a cancelled request\n");
373 } else {
374 spin_unlock(&m->req_lock);
375 p9_debug(P9_DEBUG_ERROR,
376 "Request tag %d errored out while we were reading the reply\n",
377 m->rc.tag);
378 err = -EIO;
379 goto error;
380 }
381 spin_unlock(&m->req_lock);
382 m->rc.sdata = NULL;
383 m->rc.offset = 0;
384 m->rc.capacity = 0;
385 p9_req_put(m->client, m->rreq);
386 m->rreq = NULL;
387 }
388
389end_clear:
390 clear_bit(Rworksched, &m->wsched);
391
392 if (!list_empty(&m->req_list)) {
393 if (test_and_clear_bit(Rpending, &m->wsched))
394 n = EPOLLIN;
395 else
396 n = p9_fd_poll(m->client, NULL, NULL);
397
398 if ((n & EPOLLIN) && !test_and_set_bit(Rworksched, &m->wsched)) {
399 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
400 schedule_work(&m->rq);
401 }
402 }
403
404 return;
405error:
406 p9_conn_cancel(m, err);
407 clear_bit(Rworksched, &m->wsched);
408}
409
410/**
411 * p9_fd_write - write to a socket
412 * @client: client instance
413 * @v: buffer to send data from
414 * @len: size of send buffer
415 *
416 */
417
418static int p9_fd_write(struct p9_client *client, void *v, int len)
419{
420 ssize_t ret;
421 struct p9_trans_fd *ts = NULL;
422
423 if (client && client->status != Disconnected)
424 ts = client->trans;
425
426 if (!ts)
427 return -EREMOTEIO;
428
429 if (!(ts->wr->f_flags & O_NONBLOCK))
430 p9_debug(P9_DEBUG_ERROR, "blocking write ...\n");
431
432 ret = kernel_write(ts->wr, v, len, &ts->wr->f_pos);
433 if (ret <= 0 && ret != -ERESTARTSYS && ret != -EAGAIN)
434 client->status = Disconnected;
435 return ret;
436}
437
438/**
439 * p9_write_work - called when a transport can send some data
440 * @work: container for work to be done
441 *
442 */
443
444static void p9_write_work(struct work_struct *work)
445{
446 __poll_t n;
447 int err;
448 struct p9_conn *m;
449 struct p9_req_t *req;
450
451 m = container_of(work, struct p9_conn, wq);
452
453 if (m->err < 0) {
454 clear_bit(Wworksched, &m->wsched);
455 return;
456 }
457
458 if (!m->wsize) {
459 spin_lock(&m->req_lock);
460 if (list_empty(&m->unsent_req_list)) {
461 clear_bit(Wworksched, &m->wsched);
462 spin_unlock(&m->req_lock);
463 return;
464 }
465
466 req = list_entry(m->unsent_req_list.next, struct p9_req_t,
467 req_list);
468 WRITE_ONCE(req->status, REQ_STATUS_SENT);
469 p9_debug(P9_DEBUG_TRANS, "move req %p\n", req);
470 list_move_tail(&req->req_list, &m->req_list);
471
472 m->wbuf = req->tc.sdata;
473 m->wsize = req->tc.size;
474 m->wpos = 0;
475 p9_req_get(req);
476 m->wreq = req;
477 spin_unlock(&m->req_lock);
478 }
479
480 p9_debug(P9_DEBUG_TRANS, "mux %p pos %d size %d\n",
481 m, m->wpos, m->wsize);
482 clear_bit(Wpending, &m->wsched);
483 err = p9_fd_write(m->client, m->wbuf + m->wpos, m->wsize - m->wpos);
484 p9_debug(P9_DEBUG_TRANS, "mux %p sent %d bytes\n", m, err);
485 if (err == -EAGAIN)
486 goto end_clear;
487
488
489 if (err < 0)
490 goto error;
491 else if (err == 0) {
492 err = -EREMOTEIO;
493 goto error;
494 }
495
496 m->wpos += err;
497 if (m->wpos == m->wsize) {
498 m->wpos = m->wsize = 0;
499 p9_req_put(m->client, m->wreq);
500 m->wreq = NULL;
501 }
502
503end_clear:
504 clear_bit(Wworksched, &m->wsched);
505
506 if (m->wsize || !list_empty(&m->unsent_req_list)) {
507 if (test_and_clear_bit(Wpending, &m->wsched))
508 n = EPOLLOUT;
509 else
510 n = p9_fd_poll(m->client, NULL, NULL);
511
512 if ((n & EPOLLOUT) &&
513 !test_and_set_bit(Wworksched, &m->wsched)) {
514 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
515 schedule_work(&m->wq);
516 }
517 }
518
519 return;
520
521error:
522 p9_conn_cancel(m, err);
523 clear_bit(Wworksched, &m->wsched);
524}
525
526static int p9_pollwake(wait_queue_entry_t *wait, unsigned int mode, int sync, void *key)
527{
528 struct p9_poll_wait *pwait =
529 container_of(wait, struct p9_poll_wait, wait);
530 struct p9_conn *m = pwait->conn;
531 unsigned long flags;
532
533 spin_lock_irqsave(&p9_poll_lock, flags);
534 if (list_empty(&m->poll_pending_link))
535 list_add_tail(&m->poll_pending_link, &p9_poll_pending_list);
536 spin_unlock_irqrestore(&p9_poll_lock, flags);
537
538 schedule_work(&p9_poll_work);
539 return 1;
540}
541
542/**
543 * p9_pollwait - add poll task to the wait queue
544 * @filp: file pointer being polled
545 * @wait_address: wait_q to block on
546 * @p: poll state
547 *
548 * called by files poll operation to add v9fs-poll task to files wait queue
549 */
550
551static void
552p9_pollwait(struct file *filp, wait_queue_head_t *wait_address, poll_table *p)
553{
554 struct p9_conn *m = container_of(p, struct p9_conn, pt);
555 struct p9_poll_wait *pwait = NULL;
556 int i;
557
558 for (i = 0; i < ARRAY_SIZE(m->poll_wait); i++) {
559 if (m->poll_wait[i].wait_addr == NULL) {
560 pwait = &m->poll_wait[i];
561 break;
562 }
563 }
564
565 if (!pwait) {
566 p9_debug(P9_DEBUG_ERROR, "not enough wait_address slots\n");
567 return;
568 }
569
570 pwait->conn = m;
571 pwait->wait_addr = wait_address;
572 init_waitqueue_func_entry(&pwait->wait, p9_pollwake);
573 add_wait_queue(wait_address, &pwait->wait);
574}
575
576/**
577 * p9_conn_create - initialize the per-session mux data
578 * @client: client instance
579 *
580 * Note: Creates the polling task if this is the first session.
581 */
582
583static void p9_conn_create(struct p9_client *client)
584{
585 __poll_t n;
586 struct p9_trans_fd *ts = client->trans;
587 struct p9_conn *m = &ts->conn;
588
589 p9_debug(P9_DEBUG_TRANS, "client %p msize %d\n", client, client->msize);
590
591 INIT_LIST_HEAD(&m->mux_list);
592 m->client = client;
593
594 spin_lock_init(&m->req_lock);
595 INIT_LIST_HEAD(&m->req_list);
596 INIT_LIST_HEAD(&m->unsent_req_list);
597 INIT_WORK(&m->rq, p9_read_work);
598 INIT_WORK(&m->wq, p9_write_work);
599 INIT_LIST_HEAD(&m->poll_pending_link);
600 init_poll_funcptr(&m->pt, p9_pollwait);
601
602 n = p9_fd_poll(client, &m->pt, NULL);
603 if (n & EPOLLIN) {
604 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
605 set_bit(Rpending, &m->wsched);
606 }
607
608 if (n & EPOLLOUT) {
609 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
610 set_bit(Wpending, &m->wsched);
611 }
612}
613
614/**
615 * p9_poll_mux - polls a mux and schedules read or write works if necessary
616 * @m: connection to poll
617 *
618 */
619
620static void p9_poll_mux(struct p9_conn *m)
621{
622 __poll_t n;
623 int err = -ECONNRESET;
624
625 if (m->err < 0)
626 return;
627
628 n = p9_fd_poll(m->client, NULL, &err);
629 if (n & (EPOLLERR | EPOLLHUP | EPOLLNVAL)) {
630 p9_debug(P9_DEBUG_TRANS, "error mux %p err %d\n", m, n);
631 p9_conn_cancel(m, err);
632 }
633
634 if (n & EPOLLIN) {
635 set_bit(Rpending, &m->wsched);
636 p9_debug(P9_DEBUG_TRANS, "mux %p can read\n", m);
637 if (!test_and_set_bit(Rworksched, &m->wsched)) {
638 p9_debug(P9_DEBUG_TRANS, "sched read work %p\n", m);
639 schedule_work(&m->rq);
640 }
641 }
642
643 if (n & EPOLLOUT) {
644 set_bit(Wpending, &m->wsched);
645 p9_debug(P9_DEBUG_TRANS, "mux %p can write\n", m);
646 if ((m->wsize || !list_empty(&m->unsent_req_list)) &&
647 !test_and_set_bit(Wworksched, &m->wsched)) {
648 p9_debug(P9_DEBUG_TRANS, "sched write work %p\n", m);
649 schedule_work(&m->wq);
650 }
651 }
652}
653
654/**
655 * p9_fd_request - send 9P request
656 * The function can sleep until the request is scheduled for sending.
657 * The function can be interrupted. Return from the function is not
658 * a guarantee that the request is sent successfully.
659 *
660 * @client: client instance
661 * @req: request to be sent
662 *
663 */
664
665static int p9_fd_request(struct p9_client *client, struct p9_req_t *req)
666{
667 __poll_t n;
668 struct p9_trans_fd *ts = client->trans;
669 struct p9_conn *m = &ts->conn;
670
671 p9_debug(P9_DEBUG_TRANS, "mux %p task %p tcall %p id %d\n",
672 m, current, &req->tc, req->tc.id);
673
674 spin_lock(&m->req_lock);
675
676 if (m->err < 0) {
677 spin_unlock(&m->req_lock);
678 return m->err;
679 }
680
681 WRITE_ONCE(req->status, REQ_STATUS_UNSENT);
682 list_add_tail(&req->req_list, &m->unsent_req_list);
683 spin_unlock(&m->req_lock);
684
685 if (test_and_clear_bit(Wpending, &m->wsched))
686 n = EPOLLOUT;
687 else
688 n = p9_fd_poll(m->client, NULL, NULL);
689
690 if (n & EPOLLOUT && !test_and_set_bit(Wworksched, &m->wsched))
691 schedule_work(&m->wq);
692
693 return 0;
694}
695
696static int p9_fd_cancel(struct p9_client *client, struct p9_req_t *req)
697{
698 struct p9_trans_fd *ts = client->trans;
699 struct p9_conn *m = &ts->conn;
700 int ret = 1;
701
702 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
703
704 spin_lock(&m->req_lock);
705
706 if (req->status == REQ_STATUS_UNSENT) {
707 list_del(&req->req_list);
708 WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
709 p9_req_put(client, req);
710 ret = 0;
711 }
712 spin_unlock(&m->req_lock);
713
714 return ret;
715}
716
717static int p9_fd_cancelled(struct p9_client *client, struct p9_req_t *req)
718{
719 struct p9_trans_fd *ts = client->trans;
720 struct p9_conn *m = &ts->conn;
721
722 p9_debug(P9_DEBUG_TRANS, "client %p req %p\n", client, req);
723
724 spin_lock(&m->req_lock);
725 /* Ignore cancelled request if message has been received
726 * before lock.
727 */
728 if (req->status == REQ_STATUS_RCVD) {
729 spin_unlock(&m->req_lock);
730 return 0;
731 }
732
733 /* we haven't received a response for oldreq,
734 * remove it from the list.
735 */
736 list_del(&req->req_list);
737 WRITE_ONCE(req->status, REQ_STATUS_FLSHD);
738 spin_unlock(&m->req_lock);
739
740 p9_req_put(client, req);
741
742 return 0;
743}
744
745static int p9_fd_show_options(struct seq_file *m, struct p9_client *clnt)
746{
747 if (clnt->trans_mod == &p9_tcp_trans) {
748 if (clnt->trans_opts.tcp.port != P9_PORT)
749 seq_printf(m, ",port=%u", clnt->trans_opts.tcp.port);
750 } else if (clnt->trans_mod == &p9_fd_trans) {
751 if (clnt->trans_opts.fd.rfd != ~0)
752 seq_printf(m, ",rfd=%u", clnt->trans_opts.fd.rfd);
753 if (clnt->trans_opts.fd.wfd != ~0)
754 seq_printf(m, ",wfd=%u", clnt->trans_opts.fd.wfd);
755 }
756 return 0;
757}
758
759/**
760 * parse_opts - parse mount options into p9_fd_opts structure
761 * @params: options string passed from mount
762 * @opts: fd transport-specific structure to parse options into
763 *
764 * Returns 0 upon success, -ERRNO upon failure
765 */
766
767static int parse_opts(char *params, struct p9_fd_opts *opts)
768{
769 char *p;
770 substring_t args[MAX_OPT_ARGS];
771 int option;
772 char *options, *tmp_options;
773
774 opts->port = P9_PORT;
775 opts->rfd = ~0;
776 opts->wfd = ~0;
777 opts->privport = false;
778
779 if (!params)
780 return 0;
781
782 tmp_options = kstrdup(params, GFP_KERNEL);
783 if (!tmp_options) {
784 p9_debug(P9_DEBUG_ERROR,
785 "failed to allocate copy of option string\n");
786 return -ENOMEM;
787 }
788 options = tmp_options;
789
790 while ((p = strsep(&options, ",")) != NULL) {
791 int token;
792 int r;
793 if (!*p)
794 continue;
795 token = match_token(p, tokens, args);
796 if ((token != Opt_err) && (token != Opt_privport)) {
797 r = match_int(&args[0], &option);
798 if (r < 0) {
799 p9_debug(P9_DEBUG_ERROR,
800 "integer field, but no integer?\n");
801 continue;
802 }
803 }
804 switch (token) {
805 case Opt_port:
806 opts->port = option;
807 break;
808 case Opt_rfdno:
809 opts->rfd = option;
810 break;
811 case Opt_wfdno:
812 opts->wfd = option;
813 break;
814 case Opt_privport:
815 opts->privport = true;
816 break;
817 default:
818 continue;
819 }
820 }
821
822 kfree(tmp_options);
823 return 0;
824}
825
826static int p9_fd_open(struct p9_client *client, int rfd, int wfd)
827{
828 struct p9_trans_fd *ts = kzalloc(sizeof(struct p9_trans_fd),
829 GFP_KERNEL);
830 if (!ts)
831 return -ENOMEM;
832
833 ts->rd = fget(rfd);
834 if (!ts->rd)
835 goto out_free_ts;
836 if (!(ts->rd->f_mode & FMODE_READ))
837 goto out_put_rd;
838 /* Prevent workers from hanging on IO when fd is a pipe.
839 * It's technically possible for userspace or concurrent mounts to
840 * modify this flag concurrently, which will likely result in a
841 * broken filesystem. However, just having bad flags here should
842 * not crash the kernel or cause any other sort of bug, so mark this
843 * particular data race as intentional so that tooling (like KCSAN)
844 * can allow it and detect further problems.
845 */
846 data_race(ts->rd->f_flags |= O_NONBLOCK);
847 ts->wr = fget(wfd);
848 if (!ts->wr)
849 goto out_put_rd;
850 if (!(ts->wr->f_mode & FMODE_WRITE))
851 goto out_put_wr;
852 data_race(ts->wr->f_flags |= O_NONBLOCK);
853
854 client->trans = ts;
855 client->status = Connected;
856
857 return 0;
858
859out_put_wr:
860 fput(ts->wr);
861out_put_rd:
862 fput(ts->rd);
863out_free_ts:
864 kfree(ts);
865 return -EIO;
866}
867
868static int p9_socket_open(struct p9_client *client, struct socket *csocket)
869{
870 struct p9_trans_fd *p;
871 struct file *file;
872
873 p = kzalloc(sizeof(struct p9_trans_fd), GFP_KERNEL);
874 if (!p) {
875 sock_release(csocket);
876 return -ENOMEM;
877 }
878
879 csocket->sk->sk_allocation = GFP_NOIO;
880 csocket->sk->sk_use_task_frag = false;
881 file = sock_alloc_file(csocket, 0, NULL);
882 if (IS_ERR(file)) {
883 pr_err("%s (%d): failed to map fd\n",
884 __func__, task_pid_nr(current));
885 kfree(p);
886 return PTR_ERR(file);
887 }
888
889 get_file(file);
890 p->wr = p->rd = file;
891 client->trans = p;
892 client->status = Connected;
893
894 p->rd->f_flags |= O_NONBLOCK;
895
896 p9_conn_create(client);
897 return 0;
898}
899
900/**
901 * p9_conn_destroy - cancels all pending requests of mux
902 * @m: mux to destroy
903 *
904 */
905
906static void p9_conn_destroy(struct p9_conn *m)
907{
908 p9_debug(P9_DEBUG_TRANS, "mux %p prev %p next %p\n",
909 m, m->mux_list.prev, m->mux_list.next);
910
911 p9_mux_poll_stop(m);
912 cancel_work_sync(&m->rq);
913 if (m->rreq) {
914 p9_req_put(m->client, m->rreq);
915 m->rreq = NULL;
916 }
917 cancel_work_sync(&m->wq);
918 if (m->wreq) {
919 p9_req_put(m->client, m->wreq);
920 m->wreq = NULL;
921 }
922
923 p9_conn_cancel(m, -ECONNRESET);
924
925 m->client = NULL;
926}
927
928/**
929 * p9_fd_close - shutdown file descriptor transport
930 * @client: client instance
931 *
932 */
933
934static void p9_fd_close(struct p9_client *client)
935{
936 struct p9_trans_fd *ts;
937
938 if (!client)
939 return;
940
941 ts = client->trans;
942 if (!ts)
943 return;
944
945 client->status = Disconnected;
946
947 p9_conn_destroy(&ts->conn);
948
949 if (ts->rd)
950 fput(ts->rd);
951 if (ts->wr)
952 fput(ts->wr);
953
954 kfree(ts);
955}
956
957/*
958 * stolen from NFS - maybe should be made a generic function?
959 */
960static inline int valid_ipaddr4(const char *buf)
961{
962 int rc, count, in[4];
963
964 rc = sscanf(buf, "%d.%d.%d.%d", &in[0], &in[1], &in[2], &in[3]);
965 if (rc != 4)
966 return -EINVAL;
967 for (count = 0; count < 4; count++) {
968 if (in[count] > 255)
969 return -EINVAL;
970 }
971 return 0;
972}
973
974static int p9_bind_privport(struct socket *sock)
975{
976 struct sockaddr_in cl;
977 int port, err = -EINVAL;
978
979 memset(&cl, 0, sizeof(cl));
980 cl.sin_family = AF_INET;
981 cl.sin_addr.s_addr = htonl(INADDR_ANY);
982 for (port = p9_ipport_resv_max; port >= p9_ipport_resv_min; port--) {
983 cl.sin_port = htons((ushort)port);
984 err = kernel_bind(sock, (struct sockaddr *)&cl, sizeof(cl));
985 if (err != -EADDRINUSE)
986 break;
987 }
988 return err;
989}
990
991
992static int
993p9_fd_create_tcp(struct p9_client *client, const char *addr, char *args)
994{
995 int err;
996 struct socket *csocket;
997 struct sockaddr_in sin_server;
998 struct p9_fd_opts opts;
999
1000 err = parse_opts(args, &opts);
1001 if (err < 0)
1002 return err;
1003
1004 if (addr == NULL || valid_ipaddr4(addr) < 0)
1005 return -EINVAL;
1006
1007 csocket = NULL;
1008
1009 client->trans_opts.tcp.port = opts.port;
1010 client->trans_opts.tcp.privport = opts.privport;
1011 sin_server.sin_family = AF_INET;
1012 sin_server.sin_addr.s_addr = in_aton(addr);
1013 sin_server.sin_port = htons(opts.port);
1014 err = __sock_create(current->nsproxy->net_ns, PF_INET,
1015 SOCK_STREAM, IPPROTO_TCP, &csocket, 1);
1016 if (err) {
1017 pr_err("%s (%d): problem creating socket\n",
1018 __func__, task_pid_nr(current));
1019 return err;
1020 }
1021
1022 if (opts.privport) {
1023 err = p9_bind_privport(csocket);
1024 if (err < 0) {
1025 pr_err("%s (%d): problem binding to privport\n",
1026 __func__, task_pid_nr(current));
1027 sock_release(csocket);
1028 return err;
1029 }
1030 }
1031
1032 err = READ_ONCE(csocket->ops)->connect(csocket,
1033 (struct sockaddr *)&sin_server,
1034 sizeof(struct sockaddr_in), 0);
1035 if (err < 0) {
1036 pr_err("%s (%d): problem connecting socket to %s\n",
1037 __func__, task_pid_nr(current), addr);
1038 sock_release(csocket);
1039 return err;
1040 }
1041
1042 return p9_socket_open(client, csocket);
1043}
1044
1045static int
1046p9_fd_create_unix(struct p9_client *client, const char *addr, char *args)
1047{
1048 int err;
1049 struct socket *csocket;
1050 struct sockaddr_un sun_server;
1051
1052 csocket = NULL;
1053
1054 if (!addr || !strlen(addr))
1055 return -EINVAL;
1056
1057 if (strlen(addr) >= UNIX_PATH_MAX) {
1058 pr_err("%s (%d): address too long: %s\n",
1059 __func__, task_pid_nr(current), addr);
1060 return -ENAMETOOLONG;
1061 }
1062
1063 sun_server.sun_family = PF_UNIX;
1064 strcpy(sun_server.sun_path, addr);
1065 err = __sock_create(current->nsproxy->net_ns, PF_UNIX,
1066 SOCK_STREAM, 0, &csocket, 1);
1067 if (err < 0) {
1068 pr_err("%s (%d): problem creating socket\n",
1069 __func__, task_pid_nr(current));
1070
1071 return err;
1072 }
1073 err = READ_ONCE(csocket->ops)->connect(csocket, (struct sockaddr *)&sun_server,
1074 sizeof(struct sockaddr_un) - 1, 0);
1075 if (err < 0) {
1076 pr_err("%s (%d): problem connecting socket: %s: %d\n",
1077 __func__, task_pid_nr(current), addr, err);
1078 sock_release(csocket);
1079 return err;
1080 }
1081
1082 return p9_socket_open(client, csocket);
1083}
1084
1085static int
1086p9_fd_create(struct p9_client *client, const char *addr, char *args)
1087{
1088 int err;
1089 struct p9_fd_opts opts;
1090
1091 err = parse_opts(args, &opts);
1092 if (err < 0)
1093 return err;
1094 client->trans_opts.fd.rfd = opts.rfd;
1095 client->trans_opts.fd.wfd = opts.wfd;
1096
1097 if (opts.rfd == ~0 || opts.wfd == ~0) {
1098 pr_err("Insufficient options for proto=fd\n");
1099 return -ENOPROTOOPT;
1100 }
1101
1102 err = p9_fd_open(client, opts.rfd, opts.wfd);
1103 if (err < 0)
1104 return err;
1105
1106 p9_conn_create(client);
1107
1108 return 0;
1109}
1110
1111static struct p9_trans_module p9_tcp_trans = {
1112 .name = "tcp",
1113 .maxsize = MAX_SOCK_BUF,
1114 .pooled_rbuffers = false,
1115 .def = 0,
1116 .create = p9_fd_create_tcp,
1117 .close = p9_fd_close,
1118 .request = p9_fd_request,
1119 .cancel = p9_fd_cancel,
1120 .cancelled = p9_fd_cancelled,
1121 .show_options = p9_fd_show_options,
1122 .owner = THIS_MODULE,
1123};
1124MODULE_ALIAS_9P("tcp");
1125
1126static struct p9_trans_module p9_unix_trans = {
1127 .name = "unix",
1128 .maxsize = MAX_SOCK_BUF,
1129 .def = 0,
1130 .create = p9_fd_create_unix,
1131 .close = p9_fd_close,
1132 .request = p9_fd_request,
1133 .cancel = p9_fd_cancel,
1134 .cancelled = p9_fd_cancelled,
1135 .show_options = p9_fd_show_options,
1136 .owner = THIS_MODULE,
1137};
1138MODULE_ALIAS_9P("unix");
1139
1140static struct p9_trans_module p9_fd_trans = {
1141 .name = "fd",
1142 .maxsize = MAX_SOCK_BUF,
1143 .def = 0,
1144 .create = p9_fd_create,
1145 .close = p9_fd_close,
1146 .request = p9_fd_request,
1147 .cancel = p9_fd_cancel,
1148 .cancelled = p9_fd_cancelled,
1149 .show_options = p9_fd_show_options,
1150 .owner = THIS_MODULE,
1151};
1152MODULE_ALIAS_9P("fd");
1153
1154/**
1155 * p9_poll_workfn - poll worker thread
1156 * @work: work queue
1157 *
1158 * polls all v9fs transports for new events and queues the appropriate
1159 * work to the work queue
1160 *
1161 */
1162
1163static void p9_poll_workfn(struct work_struct *work)
1164{
1165 unsigned long flags;
1166
1167 p9_debug(P9_DEBUG_TRANS, "start %p\n", current);
1168
1169 spin_lock_irqsave(&p9_poll_lock, flags);
1170 while (!list_empty(&p9_poll_pending_list)) {
1171 struct p9_conn *conn = list_first_entry(&p9_poll_pending_list,
1172 struct p9_conn,
1173 poll_pending_link);
1174 list_del_init(&conn->poll_pending_link);
1175 spin_unlock_irqrestore(&p9_poll_lock, flags);
1176
1177 p9_poll_mux(conn);
1178
1179 spin_lock_irqsave(&p9_poll_lock, flags);
1180 }
1181 spin_unlock_irqrestore(&p9_poll_lock, flags);
1182
1183 p9_debug(P9_DEBUG_TRANS, "finish\n");
1184}
1185
1186static int __init p9_trans_fd_init(void)
1187{
1188 v9fs_register_trans(&p9_tcp_trans);
1189 v9fs_register_trans(&p9_unix_trans);
1190 v9fs_register_trans(&p9_fd_trans);
1191
1192 return 0;
1193}
1194
1195static void __exit p9_trans_fd_exit(void)
1196{
1197 flush_work(&p9_poll_work);
1198 v9fs_unregister_trans(&p9_tcp_trans);
1199 v9fs_unregister_trans(&p9_unix_trans);
1200 v9fs_unregister_trans(&p9_fd_trans);
1201}
1202
1203module_init(p9_trans_fd_init);
1204module_exit(p9_trans_fd_exit);
1205
1206MODULE_AUTHOR("Eric Van Hensbergen <ericvh@gmail.com>");
1207MODULE_DESCRIPTION("Filedescriptor Transport for 9P");
1208MODULE_LICENSE("GPL");